Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Tissue distribution and regulation of calcium concentration, Define Tissue ...

Define Tissue Distribution and Regulation of Calcium Concentration? As already discussed, development and preservation of bone mass is quantitatively an important function of c

Hormones secreted by pituitary gland, (a) Hormones of the Anterior lobe - ...

(a) Hormones of the Anterior lobe - The anteriorIobe of the pituitary gland secretes the following hormones, most of them are trophic hormones. (i ) Somatotropic hormone o

Types of stem cells-pulp tissue revascularization, Embryonic stem cells: c...

Embryonic stem cells: can differentiate into all cell types of the specialized embryonic tissues when given sufficient and necessary stimulation for a specific cell type, e.g. Plu

Which type of gamete produced by a heterozygous individual, Which is the ty...

Which is the type of gamete produced by a heterozygous individual? What is the genotypical proportion of these gametes? Heterozygous individuals, for instance, AA, produce two

Plot the amount of dna in the nucleus, Plot the amount of DNA in the nucleu...

Plot the amount of DNA in the nucleus of spermatogonia from the G1 stage prior to the first meiotic division through the completion of meiosis. Label each of the major stages of th

Degradation of ecosystem, Degradation of Ecosystem Ancient man was si...

Degradation of Ecosystem Ancient man was simple-minded food gatherer and hunter. He looked upon nature with awe and respect and in fact he worshipped it. But from the time he

Anticoagulation, In patients with left ventricular failure and reduced ejec...

In patients with left ventricular failure and reduced ejection fractions, the risk of LV thrombus formation and systemic arterial embolization appears to be primarily in patients

What are genetic mutations, What are genetic mutations? The Genetic mut...

What are genetic mutations? The Genetic mutations are alterations of the genetic material (compared to the normal condition of the species) involving modifications in the norma

Signify asexual and how it is formed, Signify Asexual and how it is formed?...

Signify Asexual and how it is formed? Organisms which do not reproduce by recombination of genetic material contained in gametes. There is not any combination of a haploid sper

Simplified bernoulli equation, The simplified Bernoulli equation may be  ap...

The simplified Bernoulli equation may be  applied to peak velocity measurements to make non-invasive estimates of pressure gradients. Where  Vl = peak velocity proximal to an obstr

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd